Attorney-client conversations and other private communications were secretly recorded with surveillance cameras at police headquarters in Edison, N.J., though the police chief had promised that the microphones would be disabled.

It’s unclear how long the audio has been recorded, the New Jersey Star-Ledger reports. The cameras were installed in January, and one police union official said he suspects the audio has been on the entire time.

Police Chief Thomas Bryan, however, said he was informed by the company that installed the cameras that the problem developed only about two weeks ago. The company has accepted responsibility for the error and has acknowledged it had been instructed to disable the audio, Bryan said in a statement.

“Once we were made aware that the microphones on the entire system were active, we took immediate corrective action to disable the audio microphones throughout the police department,” Bryan said.

Forty cameras were operating in the building, including one in a hallway outside internal affairs where officers sometimes speak to their lawyers, the story says. Another camera was in the hallway outside municipal court where lawyers speak with clients.

James Mets, a lawyer for the Superior Officers Association, says the recordings may violate state and federal wiretap laws.

On Wednesday, the county prosecutor’s office seized several police computer servers used to store videos from the cameras, two law enforcement officials told the Star Ledger. A spokesman for the office would neither confirm nor deny an investigation.